a) Field of the Invention
This invention relates to hydrophilic adhesive masses and hydrophilic plasters, and specifically to hydrophilic adhesive masses, which are strong in adhesiveness and excellent in feeling of use, and also to hydrophilic plasters making use of the same.
b) Description of the Related Art
Hydrophilic plasters each of which carries a hydrophilic mass having adhesiveness and spread as an external preparation on a backing have been used for years. These hydrophilic plasters are required to remain in firm adherence to skin without peeling off during application.
Conventional plasters are known to include non-gelatin poultice composed of polyacrylic acid, a polyacrylate salt, carboxymethylcellulose and an alkali metal alginate (JP 59-110617 A); transdermal preparations composed of polyacrylic acid a 10% aqueous solution of which has a viscosity of from 100 to 1,000 cps, a water-soluble polymer, a polyhydric alcohol and water (JP 6-135828 A); water-containing gel plasters composed of an N-vinylacetamide-sodium acrylate copolymer, a water-soluble aluminum salt and water (JP 9-143060 A); and cataplasms added with polybutene and gelatin (JP 9-208462 A). They are however accompanied with one or more problems such as insufficient adhesiveness and/or difficulty in commercial production.